Drill attachment



Jan. 2, 1962 c. D. HODNETT 3,015,240

DRILL. ATTACHMENT Filed oct. 25, 1959 IN VEN TOR.

United States Patent O 3,015,240 DRILL ATTACHMENT Carl D. Hodnett, Rte.3, Box 252, Goldsboro, N.C. Filed Oct. 23, 1959, Ser. No. 848,347 2Claims. (Cl. 77-55) This invention relates to a novel attachment forpower drills for holding and centering such as the heads of bolts,relative to the drills while drilling the bolts for their removal fromplates secured together by the bolts.

The primary object of the invention is to provide an eicient, easilyinstallable attachment of the kind indicated, especially but notexclusively, for air operated drills used in aircraft construction andrepair work, which facilitates and speeds the removal, without damage toplates, of Jo-bolts, thereby saving labor, time, and material.

Another object of the invention is to provide a simple and rugged deviceof the character indicated above, which is composed of only tworelatively movable parts, other than a spring tensioning these partsaway from each other, one of which serves as an adjustable holder `for aremovable Io-bolt set.

Other important objects and advantageous features of the invention willbe apparent from the following description and the accompanyingdrawings, wherein, for purposes of illustration only, a specific form ofthe invention is set forth in detail.

In the drawings:

FIGURE l is a vertical transverse section taken through a device of theinvention, showing the same installed on an air-operated drill casing;

FIGURE 2 is a horizontal section taken on the line 2 2 of FIGURE l;

`FIGURE 3 is a side elevation, partly broken away in section, of theupper barrel of the device;

FIGURE 4 is a horizontal section taken on tbe line 4-4 of FIGURE 3;

FIGURE 5 is a side elevation of the expanding spring;

FIGURE 6 is a horizontal section taken on the line 6--6 of FIGURE 5;

FIGURE 7 is a side elevation of the Io-bolt set mounting ring;

FIGURE 8 is a top plan view of said ring;

FIGURE 9 is a side elevation of the lower barrel of the device, partlybroken away and in section; and

FIGURE l0 is a horizontal section taken on the line 1li-1l) of FIGURE 9.

Referring in detail to the drawings, wherein like numerals designatelike parts throughout the several views, the illustrated device,generally designated 10, comprises a barrel composed of an uppermounting barrel section 12, a lower slideway barrel section 14, aJo-bolt set mounting and slide ring 16 working in the lower barrelsection, an expanding spring 18 compressed between the ring 16 and theupper barrel section 12, and a Io-bolt set 2i) secured in the ring 16. i

The upper barrel section 12 comprises a tubular cylinder having aninternally threaded upper end 22 to be threaded, as indicated at 24, onthe lower end of the casing 26, of a drill, such as an air-operateddrill as used in aircraft construction and repair; with the drill chuck28 extending below the casing 26, out of contact with the upper barrelsection 12, and having a drill bit 30 chucked therein. The upper barrelsection 12 is open at its lower end and is yformed thereat with areduced diameter inwardly offset terminal 32, which, at its inward side,provides an annular stop shoulder 34, spaced upwardly from the lower end36 of the terminal, and external screw threads 3S below an externalshoulder 40, spaced above the internal shoulder 34.

The lower or slideway barrel section 14 comprises a ice tubular cylinderhaving a partially closed lower end 42, provided with a central axialopening 44, and having a side wall 46 which is formed with a pair ofdiametrically opposed, closed vertical slots 48. The lower barrelsection 14 is preferably of the same outside diameter as the upperbarrel section 12, and has in its upper end a threaded socket 50 intowhich the upper barrel section terminal 32 is threaded, to connect thebarrel sections together.

The slide ring 16 is a relatively large cross section annulus of anoutside diameter to slide snugly in the bore 52 or' the lower barrelsection 14, and has a central axial threaded opening S4. Diametricallyopposed radial threaded sockets 56 opening to the peripheral edge 58 ofthe ring have threaded therein studs 60 which engage slidably throughrelated ones of the slots 48 and have enlarged heads 62 on their outerends to bear against the exterior of the lower barrel section 14.

The expansion spring 18 is a relatively heavy helical spring which isconfined in the -lower barrel section 14, spacedly surrounds the drillbit 30, and is spaced close to the bore 52, and is compressed betweenthe internal shoulder 34 of the upper barrel section 12, and the top ofthe slide ring 16, and serves to normally engage the ring 16, with theclosed lower end 42 of the lower barrel section 14, as shown in lFIGURE1, so as to fully extend the I o-bolt nut engager set 20.

The Jo-bolt set 20, for which substitutions can be made depending uponthe work to be done, comprises a tubular shank 64 of an inside diameterto rotatably and slidably receive the drill bit. The shank 64 has athreaded upper end 66 which extends freely through the opening 44 in thelower end of the lower barrel section and is threaded into the opening54 of the slide ring 16. The shank 64 has an enlarged diametercup-shaped head 68 on its lower end, providing a nut receiving socket 70of the shape of the nut 72 of a Io-bolt 74 extending through engagedplates 76 and 78, from which the bolt is to be removed by drilling thesame to the extent necessary to eect its easy removal. As shown inFIGURE 1, the socket 7i) is shallower than the nut 72, so that the lowerend 8l) of the socket is kept out of contact with the work from whichthe bolt is to be drilled until the bolt has been drilled down.

It will be understood from the foregoing that the drill case 26 beingheld stationary and the socket 70 being engaged runder pressure with thenut 72, and the drill being put into operation, the set 20 is heldagainst rotation, relative to the nut 72 and to the device 10, by reasonof the engagement of the studs 6l) with the slots 48 in the side wall 46of the lower barrel section 14, and the spring 18 enables cushionedapplication of the necessary pressure upon the nut 72, while the drillbit 30 is rotated in contact with the bolt 74, and that the bit 36 iskept eentered on the bolt.

Although there has been shown and described herein a preferred form ofthe invention, it is to be understood that the invention is notnecessarily confined thereto, and thatany change or changes in thestructure of and in the Y relative arrangements 'of components thereofare contemplated as being within the scope of the invention as definedby the claims appended hereto.

What is claimed is:

l. In combination, a drill having a casing, a rotary chuck mounted onthe casing and depending below the lower end of the casing, a drill bitchucked in the chuck and extending downwardly therefrom, a tubularbarrel secured on the lower end of the drill case and extendingdownwardly therefrom, said barrel having a lower end wall having anaxial opening larger in diameter than the drill bit, a ring slidingwithin the barrel above said lower end wall, the barrel having a sidewall formed with closed vertical slots, studs on the slide ringextending out through and sliding in related slots, a helicalcompression spring Within the barrel surrounding and out of contact withthe drill bit, said spring being compressed between said ring and anupper part of the barrel, said ring having a central opening forattachment of an implement thereto, said barrel comprising an upperbarrel section and a lower barrel section having an upper end removablyand nonrotatably connected with the lower end of the upper bar relsection, the fupper barrel section being threaded on the drill casingand the lower barrel section being threaded on the upper barrel section.

2. In combination, a drill having a casing, a rotary chuck mounted onthe casing and depending below the lower end of the casing, a drill bitchucked in the chuck vand extending downwardly therefrom, a tubularbarrel secured on the lower end of the drill case Vand extendingdownwardly therefrom, said barrel having a lower end wall having anaxial opening larger in diameter than the drill bit, a ring slidingwithin the barrel above said lower end wall, the barrel having a sidewall formed with closed Vertical slots, studs on the slide ringextending out through and sliding in related slots, a helicalcompression spring, within the barrel surrounding and out of contactwith the drill bit, said spring being compressed between said ring andan upper part of the barrel, said ring having a central opening forattachment of an implement thereto, said implement comprising a tubularstem having an upper end securably engaged in the opening of the ringand extending freely through the opening in the lower end wall of thebarrel, said stem having a bore vrotatably and slidable receiving thedrill bit, said stem having a lower end having an enlarged head iixedthereon and having a nut-receiving socket in itsllower end, said barrelcomprising an upper barrel section and a lower barrel section, saidlower section having an upper end removably and non-rotatably connectedwith the lower end of the upper barrel section, said upper barrelsection having an internal shoulder against which the upper lend of thespring bears, the upper Vbarrel sectionrbeing threaded on the drillcasing and the lower barrel section being threaded on the upper barrelsection.

' References Cited in the lile of this patent UNITED STATES PATENTS2,375,112 Kanihan May 1, 1945 FOREIGN PATENTS 510,482 Great Britain Aug.2, 1939 916,987 France May 1, 1945

